NOTES OX PYRAMIDKLLID.K—DALL AXD HARTSCII. 351 



posterior portion of the whorls, where the ribs are thickened, but 

 anterior to these thickenings they are ver}^ regular and regularly- 

 spaced. There are eighteen on the tifth and twenty-six on the penul- 

 timate whorl. Periphery and base of the last whorl well rounded, the 

 latter marked by the strong continuations of the axial ribs, which 

 extend almost undiminished to the umbilical region. The intercostal 

 spaces on the base are marked like those between the sutures by 

 twenty-two incised spiral lines. Sutures Avell marked. Aperture 

 moderately large, posterior angle acute, outer lip thin, showing the 

 external sculpture within; junction of columella and outer lip well 

 rounded; columella decidedly curved, thin, somewhat re volute, pro- 

 vided with a prominent oblique fold, a little anterior to its insertion. 

 This fold joins the columella in such a manner as to give this a decid-" 

 edly sigmoid curve. Parietal wall without callus. 



Garrett's types embrace six specimens, all from the Viti Islands. 

 The best developed one is here described and ligured. It has eight 

 post-nuclear whorls, and measures: long. 4 nun.; diam. 1,7 mm. The 

 specimens belong to the Academy of Natural Sciences, Philadelphia, 

 where they are entered as No. 58110. P. Fischer" considered this 

 species synomymous with Odostoinia { = Pi/Tgulina) intcrstriata Sou- 

 verbie. In this we do not agree with him, but consider the present 

 species distinct. 



ODOSTOMIA (PYRGULINA) DENSECOSTATA UPOLUENSIS, new sub- 

 species. 



Plate XVIII, fig. 1. 



Shell elongate-conic, subturrited, early whorls bluish-white, later 

 ones milk-white. Nuclear whorls small, almost completely obliquely 

 immersed in the first post-nuclear whorl; only half of the tilted last 

 volution can be seen. Post-nuclear whorls slightly rounded, the 

 posterior two-thirds between the sutures almost flattened, somewhat 

 shouldered, marked by strong obliquely backward-slanting rounded 

 axial ribs which are somewhat thickened and subcuspidate at the sum- 

 mits; fourteen of these ribs occur upon the first, eighteen upon the 

 third, twenty-four upon the fifth and on the penultimate whorl. Inter- 

 costal spaces somewhat variable in width, one to one and one-half 

 times as wide as the ribs, crossed b}' fine subequal and subequailj^ 

 spaced impressed spiral lines, the spaces between them being a little 

 wider than the impressed lines; about twent}' of these lines occur 

 between the sutures on the fifth and twenty-two upon the penultimate 

 whorl. Periphery and base of the last whorl well rounded, the latter 

 marked like the spaces between the sutures by the strong continuation 

 of the axial ribs, wliich extend undiminished to the small umbilical 



«Jour. (le Conch., XXIV, 1876, p. 150. 



